﻿<%@ Application Language="C#" %>

<script runat="server">

    void Application_Start(object sender, EventArgs e) 
    {
        // Code that runs on application startup
        Application["online"] = 0;
    }
    
    void Application_End(object sender, EventArgs e) 
    {
        //  Code that runs on application shutdown

    }
        
    void Application_Error(object sender, EventArgs e) 
    { 
        // Code that runs when an unhandled error occurs

    }

    void Session_Start(object sender, EventArgs e) 
    {
        // Code that runs when a new session is started
        Application.Lock();
        Application["online"] = (int)Application["online"] + 1;
        Application.UnLock();
        int count_visit = 0;

        //Kiểm tra file count_visit.txt nếu không tồn tại thì         
        if (System.IO.File.Exists(Server.MapPath("count_visit.txt")) == false)
        {
            count_visit = 1;
        }
        // Ngược lại thì      
        else
        {
            // Đọc dử liều từ file count_visit.txt    
            System.IO.StreamReader read = new System.IO.StreamReader(Server.MapPath("count_visit.txt"));
            count_visit = int.Parse(read.ReadLine());
            read.Close();
            // Tăng biến count_visit thêm 1      
            count_visit++;
        }

        // khóa website         
        Application.Lock();

        // gán biến Application count_visit     
        Application["count_visit"] = count_visit;

        // Mở khóa website    
        Application.UnLock();

        // Lưu dử liệu vào file count_visit.txt     
        System.IO.StreamWriter writer = new System.IO.StreamWriter(Server.MapPath("count_visit.txt"));
        writer.WriteLine(count_visit);
        writer.Close();
    }

    void Session_End(object sender, EventArgs e) 
    {
        // Code that runs when a session ends. 
        // Note: The Session_End event is raised only when the sessionstate mode
        // is set to InProc in the Web.config file. If session mode is set to StateServer 
        // or SQLServer, the event is not raised.
        Application.Lock();
        Application["online"] = (int)Application["online"] - 1;
        Application.UnLock();        
    }
       
</script>
